Flow Structure in the Near-Wall Region of a Submerged Impinging Jet

An experimental investigation was performed to study the flow structure of a submerged water jet impinging normally on a smooth and flat surface using Particle Image Velocimetry (PIV). The jet issued from a 112 diameter, D, long pipe which ensured fully-developed turbulent flow conditions at the outlet. A semi-confined setting provided properly characterized flow boundary conditions. The Reynolds number based on jet mean exit velocity was Re = 16,000. The pipe-to-plate separation was varied between 1 and 8 pipe diameters. The current study focused on characterizing the flow structure close to the pipe outlet in the impingement and wall-jet regions. Statistically averaged mean and RMS velocities are reported for a 6D wide and 1D high, near-plate, rectangular region. A total of 155 × 24 or 3720 vectors were obtained, each representing the spatial average over a 0.0394D × 0.0394D area.